Here's a few do's and don't for attending writing conferences.
DO study and research the agents and/or editors that will be there if you are going to pitch to them. If they don't deal with what your write, don't waste their time or yours.
DO be friendly. Talk to others, mingle and make some new friends. Need a conversation starter? Just ask the other person what they write. Works every time.
DO take business cards but DON't be annoying with them. When you get cards from others, make a quick note on them so you'll remember that person better.
DO be professional. DON'T hog the pros. Everyone wants to chat with that agent or editor so be considerate of others.
DO plan which workshops you want to attend beforehand. This way you know where you need to be and when you need to be there.
DON'T expect an agent or editor to take your manuscript home with them from the conference. They don't need another thing to lug around and on the plane.
DO have fun, enjoy the experience.